About the GS2 series back pressure regulators

Cv: 1·E-03 to 1.20  |  Max. Temperature: 300°C  |  Max. Pressure: 172 barg (2500 PSI)


The GS2 series consists of the GSD2, GSDM2 and GSDH2 units. This series is Equilibar’s smallest unit in the general service series and has some overlap with Equilibar’s research series. “Small” is a bit misleading since the capacity of this is actually very large. The unit has a diameter of only 76 mm and a Cv value of 1,2. The rangeability of this unit is just like any other back pressure regulator, namely very large. When using a polymeric diaphragm it goes all the way down to 10E-3.

Customers use the GSD2 series back pressure regulators often in high flow catalytic research applications or small pilot plants. Another common application is high viscous media. Customers use the Equilibar® back pressure control valves successfully with viscosities up to 10.000 cP.

Applications like research vacuum distillation are also likely to benefit from the high capacity. You can use a dome-loaded back pressure regulator as a vacuum regulator when the required vacuum is set to the reference port. When controlling a certain mass flow rate under sub-atmospheric conditions, the volume flow increases. This requires a large flow capacity that is offered by this small 1/4″ unit.

At the high-pressure spectrum, the GSDM2 and GSDH2 are available. These units have a slightly larger footprint, but more important a thicker body to withstand pressures of 69 bar (1000 PSI) all the way up to 172 bar (2500 PSI).

In some cases, we also design something new. A special GSDH2 back pressure regulator was designed so it can handle a pressure of 250 bar gauge at a maximum of 300°C, with a required Cv of 1.7. You can more information about this in our blog: “Special GSDH2 Back Pressure Regulator”.


The most common construction material that customers use is stainless steel 316. However, customers also use Hastelloy or PTFE often for harsh chemicals in vacuum distillation. Customers use anodized alumina for inert gasses and/or liquids from vacuum up to 27 bar gauge. For fir instance hot hydrogen chloride solution, we provide units made of Zirconium. The construction of an Equilibar product makes it also possible to apply coatings like Tantum or Silconert.

If you require a unit that can digest even more flow, larger units up to 1″ with a Cv of 8.5 are available in the General Service series.

Do you want more information about this product?

The working of an Equilibar Dome Loaded Back Pressure Regulator

How to Rebuild your Equilibar Back Pressure Regulator

Different materials that are used to make Equilibar Back Pressure Regulators and diaphragms